An issue to users and would-be users of networks, and especially largely public networks like the Internet, is how to carry out commerce in content materials which are suitable for communication across and can be made available on those networks. For example, although the World Wide Web has exhibited remarkable growth and success in recent years, it is still hampered by the lack of a satisfactory means by which some parties may sell and other parties may buy copies of content materials like text, music, still pictures, moving pictures, and potentially other materials as well. This issue becomes even more sweeping in view of the potential millions of people and businesses which may want to offer up for payment and to tender back payment for such content materials.